What If
by Anosmion
Summary: Collection of one-shots about Stiles and Derek meeting, growing up and eventually falling in love. Will feature Sterek and probably some OCs. This is an Alternate Timeline collection, meaning something didn't happen as it did in the canon Teen Wolf universe. But it still features werewolves and canon characters.


**Title**: Trick-or-Treat

**Rating**: T

**Pairings**: Kate Argent/Derek Hale

**Warnings/Notes**: teen!Derek, kid!Stiles

**Summary**: Stiles is trick-or-treating. Derek is trying to have sex. Naturally this is when they first meet. Not as sexy as it might sound because no actual Sterek. That would be pedophilia.

* * *

Every inch of Derek's being thrummed with excitement. He could smell the arousal coming off in heady waves from Kate. She'd danced around the prospect of sex for weeks, but this was the real deal.

Derek hardly associated with humans aside from a few empty words to appear polite and sociable. But Kate was so different from the others. There was something animalistic, something feral about her. A gleam in her eyes that made Derek's wolf want to howl.

"Mmmm, this is gonna' be so good," she moaned, grinding down on the obvious bulge in his pants. Derek panted breathlessly, his hands running along her sides, slipping underneath her blouse. Kate's tongue slipped into his mouth as Derek's hips rutted upwards.

Kate pushed back as hard as Derek needed it, wanted it. Derek watched as she sat a little straighter and her nimble fingers played along the buttons of her blouse. She undid each one slowly, teasing Derek. A sharp shiver of anticipation shot up Derek's spine. Soon all that fair, warm skin would be bared to him, for him, for his pleasure.

"W-wait," Derek gasped, breathless, as he tried to stay the rhythmic movement of Kate's hips.

"What's wrong?" Kate asked, easing off just a little.

"I don't wanna'- I might come- ," Derek struggled to stutter out. He might have been an adult in wolf years, but his human body was still very inexperienced.

"Oh sweetheart," Kate chuckled, smoothing a hand down Derek's chest, "don't worry about that. You're still young, that means quick recovery time. Plus you're a werewolf, that's gotta' count for something, right?" She leaned down for a slower kiss, her hair tickling Derek's ear and neck.

Derek groaned into her mouth, their hips clashing in the sweetest of ways. Kate's hands moved back to the buttons on her blouse and Derek tried desperately to regain some control of his body.

The sound of the doorbell was jarring enough to break Derek's focus on Kate. Kate groaned, "Ignore it," she said, "they'll go away." They tried to resume what they were doing. Then the doorbell rang again, and again, and again.

It was the fourth time that Derek had to break their kiss to say, "Maybe it's important."

Kate huffed impatiently, "I wasn't expecting anyone tonight."

"Want me to go check it out for you?" Derek asked. The sooner he'd get rid of whoever was at the door, the sooner he'd be able to surround himself with Kate.

"Sure," she sighed, slipping off Derek and back onto the couch. Derek stood and tried to gather his bearings. It was more difficult than usual with the scent of Kate aroused all over him. And the even more appealing _sight _of Kate on her couch, top few buttons of her blouse undone, hair tousled and lips reddened.

Derek had half a mind to ignore the doorbell altogether and go back to what they'd been doing. But suddenly it wasn't one ring, it was a barrage of rings. They pelted Derek's sensitive eardrums and he scowled in the direction of the front door. Derek stomped to the door and jerked it open.

"What?" he asked the little boy standing there dressed in a Wolverine costume.

"Trick-or-treat!" the kid shouted obnoxiously, holding open a bright orange bag with the face of a jack-o-lantern printed on the front.

"We don't have any candy, now beat it," Derek told him, then closed the door. He was just about to turn back when there was another barrage of doorbell rings.

Derek jerked the door open again. "What?" he hissed, annoyed, as he glowered down at the kid.

"What do you mean you don't have any candy?" the kid pouted.

"I mean I don't have any candy, are you stupid?" Derek asked, scowling at him.

"I'm not stupid! And it's Halloween, how come you don't have any candy?" the boy inquired, glaring up at Derek.

"Because I don't," Derek muttered through gritted teeth, "now leave," he said, letting his face shift and his eyes glow blue. The boy's eyes widened and Derek slammed the door shut on his astonished face.

Derek let out a breath, trying to ease the anger as he turned back but the doorbell rang again. Of course it did.

"Do you have a death wish or something?" he asked the kid when he opened the door, again.

"I don't know what that was, but it was cool! How'd you do it?" the boy asked, looking eagerly up at Derek. Derek was more than a little caught off guard by the smile that greeted him.

"Seriously?" Derek asked, unable to process how oblivious the boy seemed.

"My name's Stiles," the boy stated officiously, shoving past Derek and into the apartment. "I'm dressed as Wolverine, he's my favorite X-Man. Can you teach me how to do that thing with my face too?" Stiles pulled off his mask.

Derek could do nothing but gape speechlessly at the round face gazing up at him.

"Derek, is everything alright?" Kate asked, padding into the entryway of her apartment.

"Everything's fine," Derek muttered, glaring at Stiles.

"Can you do that cool thing with your face too lady? He won't show me how. My name's Stiles by the way, but I'm dressed up as Wolverine, he's my favorite X-Man," Stiles said in what Derek imagined was one endless breath, walking up to Kate.

Kate smirked. "Really," she said, crouching next to Stiles. Derek could see down her top. "Wanna' know who my favorite X-Man is?" she asked. Stiles nodded. "My favorite is Mystique," Kate told him.

"Oh, I like her too," Stiles said, "she has red hair. I like red hair. Lydia has red hair, I'm gonna' marry her one day. Do you think Lydia's name is pretty? I like it."

Kate chuckled, "Yeah, I guess Lydia's a pretty name, but my favorite name is Derek," she said, smiling up at Derek. Derek thought he felt his heart stutter at her gaze.

Stiles looked back at Derek, "Is that his name?" Stiles asked. "That's a cool name, I wish my name was Derek, but it isn't, it's- "

"Alright kid, that's enough, get out," Derek said sternly, holding the door open for him.

"But I want candy," he pouted, "it's Halloween," he said distractedly as he ventured into Kate's living room.

Derek gaped after Stiles. Then he looked at Kate who ducked her head to hide her smile as she followed Stiles into the living room.

"Well," she said, "since you've been _so _persistent, I guess I've got some dark chocolate in the fridge. You like dark chocolate?" she asked Stiles.

"I like all chocolate," Stiles grinned, hopping onto the couch Derek and Kate had just vacated. Derek cringed because their scent would probably rub off on Stiles.

"Okay, dark chocolate coming right up," Kate said, disappearing into her kitchen. Stiles looked around at everything as he fidgeted on the couch. Derek felt restless just staring at him. Suddenly Stiles sprang up from his seat and started to walk around the living room.

"Would you just sit?" Derek complained, taking a seat himself.

"Is she your girlfriend?" Stiles asked him, prodding at Kate's belongings around the room. "She's pretty," he said, "do you guys live here?" Watching Stiles move around was disorienting.

"Hey, what're these books about, did you read all of them?" Stiles asked, picking books at random out of a shelf and examining each one before placing it on the floor to move on.

"Would you just sit," Derek muttered, getting up to put the books back.

Stiles continued his trip around the living room, touching everything. "You should turn on the TV," Stiles said, "I like watching cartoons, do you like watching cartoons?"

"Hey," Derek knelt down and turned Stiles around to face him, "stop," he said, holding Stiles firmly by the wrists. Stiles looked startled, then stared wide-eyed down at Derek.

"Okay," Stiles said, except it wasn't out of fear as Derek suspected it would be. Stiles was actually calming down as he stared at Derek, even the wrists in his grasp grew a little lax

"I got the candy," Kate sang from the doorway to the kitchen, swinging a baggy of foil covered chocolates in the air. "What the hell are you doing?" she yelled at Derek when she saw him.

"No," Derek yelped, letting go of Stiles like he'd been burnt, "I wasn't, it's not what you think- ," he tried to explain.

"I _think _you were manhandling a child. Geez Derek, can't you control yourself?" Kate asked, eyeing him with a particularly vicious scowl as Derek rose to stand.

"Hey, what's this?" Stiles asked, struggling to pry the lid off a tupperware box full of purple powder.

"Where the hell did you get that?" Kate asked Stiles, her expression no longer playful as she addressed him.

"From that bag," Stiles said, gesturing at a bag peeking out from between a small table and the wall.

"Kid, do not touch my stuff. Put that away, now," Kate ordered, looking deadly serious.

"What is it?" Stiles peered curiously into the container he'd just opened. "Hey is it candy? I like Pixie Stix," Stiles said, poking his finger into the fine purple powder.

Derek didn't need to be told what it was, he was close enough to Stiles that he could smell it. The pungent aroma of wolfsbane would not be apparent to human senses. But after many many warnings from his family, it was a scent Derek was too familiar with. A scent that usually meant trouble.

"What the hell are you doing with wolfsbane?" Derek asked Kate.

Kate paused, she stared at Derek and looked away when she started to talk, "Well, you know, when you told me you were a werewolf I did some research. It's just some insurance in case you ever, I don't know, lose control or something."

Derek carefully dissected the rhythm of Kate's heartbeat. He listened for the quickening pace, for the hitches. All signs pointed to a lie, which confused Derek.

"You're lying," Derek said. Then he walked over to the bag and yanked it the rest of the way out. Inside were two guns, a crossbow, some ammo and a quiver full of arrows.

"What the hell is this?" Derek asked Kate, holding up the bag before tossing it onto the table.

Kate didn't say anything, she smirked as she strode casually over to Derek. "Okay, so you've got your secret, and I've got mine," she said.

"This," Kate said, taking out the crossbow and aiming it at Derek, "is how I kill your kind."

"You're a hunter," Derek said, taking a few steps backwards from Kate. The feeling of betrayal and the danger of being cornered writhed like two snakes in Derek's stomach. Coiling around each other, slick and sickly. Derek wanted to throw up.

"That's right kiddo'," Kate confirmed, giving Derek a slight nod. "It's a shame," Kate said, picking an arrow carefully out of the quiver, "I was hoping to kill two birds with one stone. But I guess we can always find your pack after you're dead." She loaded the crossbow.

"You- ," Derek mumbled, tripping over himself as he backed away.

"Me," Kate said, "don't run away kiddo', I'm still the same sexy 'ol Kate. The one who had you all hot and bothered a few minutes ago. Oh baby, I was gonna' take you places. Bet your friends thought you were so cool, huh? Dating an older woman? So mature."

"Didn't tell your family about me yet, did you? Do they even know where you are Derek? How depressing, you won't even get a chance to tell 'em what's coming. Goddamn shame," Kate 'tsk'-ed, shaking her head. She reveled in the vulnerability on Derek's face.

"Goddamn shame," Kate said more quietly, taking aim at Derek's chest, at his heart.

"Hey!" Stiles suddenly shouted. He tossed the box in his hands at Kate's head. It hit it's target and fell to the floor with a thunk. The lid flew off, spraying wolfsbane onto the carpet. "C'mon," Stiles said, tugging desperately at Derek's sleeve to lead him to the door.

"Damn it," Kate hissed, rubbing her forehead, "this is why I'm never having kids!" she shouted angrily, stomping after them.

Derek quickly unlocked the door and pushed Stiles out in front of him into the hallway.

"Stiles?" someone shouted in the same instant.

"Uh-oh," Stiles said, staring like a deer in headlights down the hall.

"Stiles, I told you to wait. Where did you go?" Mr. Stilinski said, walking towards Stiles and Derek.

"You little," Kate grumbled, swinging her apartment door open. When she caught sight of Officer Stilinski she quickly swung it close a little, just her head and shoulder peeking through the gap. The arm with the crossbow was carefully concealed behind the door.

"Is everything alright?" Mr. Stilinski asked, tugging Stiles closer to him.

"Everything's fine," Kate smiled pleasantly, "your son was just trick-or-treating."

"Stiles," Mr. Stilinski said, putting a hand on Stiles' shoulder, "I thought I told you to wait."

"I'm sorry dad. The candy was calling me," Stiles cried out in agony.

"What did you get all over your clothes?" he asked, brushing the purple wolfsbane powder off Stiles' costume. Derek sneezed and Mr. Stilinski looked up at him.

"You alright son?" he asked Derek. Derek realized he probably looked more than a little ruffled.

"M'fine," he replied, lowering his head.

Mr. Stilinski looked from Derek to Kate and back. "Hey, you're Derek aren't you?" Mr. Stilinski asked him. Derek looked up and nodded. "What the hell are you doing here?" he eyed Derek and Kate suspiciously.

"I was just, trick-or-treating," Derek said weakly. Mr. Stilinski raised his brows.

"Right," Kate added quickly, "and I was just telling the two of them that I don't have any candy. Goodnight," she said, smiling at Mr. Stilinski before shutting the door on them.

Mr. Stilinski looked hesitant, "Maybe I'd better drive you home son."

Derek shook his head, "I'm fine walking, sir."

"Let me rephrase that, I'm driving you home. My patrol car's a block away, c'mon," he said, not waiting for a response.

"Does this mean no more trick-or-treating tonight?" Stiles asked, tilting his head back to look at his father.

"No more trick-or-treating ever," Mr. Stilinski said, affectionately nudging Stiles' head forward.

Derek eyed Kate's door before quickly following after the Stilinskis.

* * *

"So, are you really a werewolf?" Stiles whispered when they were in the back of his dad's car. Derek really could've done without the kid sitting next to him, but Stiles insisted. The worst part was Derek could still gets whiffs of Kate and sex in the enclosed space.

"Do you ever shut up?" Derek muttered.

"That's so awesome if you are," Stiles said, "and that lady was a hunter. But I don't get it, why was she trying to kill you if she invited you to her house?" Derek turned his his head to look out the window.

"Hey," Stiles whispered, scooting uncomfortably close to Derek, "can I make that cool face if I become a werewolf?"

"Which one?" Derek asked, his eyes glowing blue when he turned back to Stiles.

Stiles looked surprised, then shouted, "Awesome!" Derek rolled his eyes.

"Stiles, stop bothering him," Mr. Stilinski scolded from the driver's seat.

"So, Derek," Mr. Stilinski asked after some silence had passed, "you wanna' tell me why you were really in that building?"

"No sir," Derek told him, polite but frank.

"You know, I'm gonna' have to tell your parents Derek," the sheriff said, catching his eyes through the rear-view mirror. Derek wanted to hop out of the car and shift. Maybe hide out in the woods for a week.

"I know sir," he said quietly instead.

"It's gonna' be okay," Stiles comforted, "my dad's the best." Derek didn't say anything.

When they got to Derek's house his mom told him to wait in the dining room while the adults talked. It wasn't everyday her baby got escorted home by a policeman. But it also wasn't like Derek couldn't hear every word they were saying.

"You," Uncle Peter said, coming into the dining room, "are in so much trouble."

"I know," Derek whined, his voice muffled because he covered his head with his hands.

"Are you a werewolf too?" Stiles asked Peter.

"Werewolf?" Peter asked, slowly walking to the back of Stiles' chair. Stiles twisted in his seat to look at Peter. "Hmm, I don't know," Peter said uncertainly. "Am I?" he hissed, suddenly an inch from Stiles' face, his own transformed halfway, eyes glowing blue.

Stiles stared wide-eyed at Peter, then smiled wide. "This-is-so-cool!" he shouted. There was a pause in the conversation in the living room.

When the talking started up again Peter raised his brows, "Cool huh?" he smirked down at Stiles. Derek rolled his eyes at his uncle's antics.

"Stiles, we're going home," Mr. Stilinski called.

" 'kay dad," Stiles shouted back, scrambling off his chair and walking out of the dining room. Derek and his uncle followed.

"We are going to talk," Derek's mom said sternly. Derek bowed his head in submission.

"Sorry for troubling you," Mr. Stilinski said, heading for the front door with Stiles in tow.

"Don't be ridiculous," Derek's father replied, "_we're_ sorry for troubling _you_."

"Dad, are we really not trick-or-treating anymore tonight?" Stiles asked, looking forlornly into his bag of candy.

"Stiles, I'm tired. You would've gotten more if you'd waited like I told you to," his dad said pointedly, patting his head.

"But dad, I have like, zero candy!" Stiles cried.

"Alright alright, we'll buy some on the way, how's that?"

"It's not the same," Stiles pouted.

"You know, we don't have candy, we don't get any kids here. But I think we've got brownies in the fridge, would you like some?" Derek's mom asked.

"Yes!" Stiles shouted.

"No," Mr. Stilinski said firmly, "he's just being difficult, we don't want to trouble you," he told Derek's mother.

"Oh, it's no trouble," Derek's mom said, "really."

Mr. Stilinski sighed, then looked down at Stiles who proceeded to whine "Pleeeeeeeeeeeeeease?"

"Alright," he relented, thumping Stiles on the forehead.

Derek's mom and the sheriff talked while his dad went to pack some brownies. Stiles bothered Derek some more. His uncle Peter found it all incredibly entertaining. When the Stilinskis were finally buckled into their car Stiles rolled his window down and poked his head out to yell, "Bye Derek!"

Derek rolled his eyes, and maybe he smiled a little when Mr. Stilinski hissed, "Stiles, sit down."


End file.
